Stage Lighting and Stadium Seating Assemblies
A top manufacturer of truss systems consulted SPIROL on an existing design of their truss system. The design was comprised of one tubular structural member and one solid male member that slid inside the tubular extrusion and was cross-pinned with two high carbon steel Slotted Pins to hold the coupler to the frame. During installation, the Slotted Pin was difficult to install and would often damage the expensive, yet relatively soft, aluminum frame. Once the hole was deformed, the manufacturer noted instances where the pin would begin to walk out of the hole over time in permanent installations. This was also noted in mobile systems if subjected to extreme loading. In some instances they had also noticed that the Slotted Pin had stress cracks located 180 degrees from the slot. In extreme weather conditions, the high carbon steel pin was also prone to corrosion. With a lack of options, the manufacturer had investigated implementation of an expensive machined Solid Pin with a secondary retention feature of a Cotter Pin. SPIROL was asked to evaluate the application and ultimately recommend the most robust and cost effective solution for this incredibly demanding application.